By sealing a light source within an enclosed environment, the operating temperature of the source is seen to increase dramatically over its designed lifetime for an open-air operating temperature. This has the effect of reducing the lamp life to the point where the lamp is non-viable for consumer use. This is a particular concern for halogen and metal halide lamps, which use molybdenum foils to make electrical connections. These foils are at risk of premature oxidation if operated at high temperatures. The premature oxidation of the molybdenum lamp connections results in early lamp failure.
The rise of a sealed system's source temperature is due in part to the insulating qualities of the stagnant air within the sealed environment. The main cause of the source's temperature rise is the inability to remove heat from the source and from the sealed environment, and then to supply cooler air to the light source. Typically, the heat transfer from the source to an often cooler outer medium is primarily by conduction through essentially stagnant air within the enclosure.
In open-air operation, a cooling fan is often used to control the temperature of a light source. This works because of the large supply of relatively cool air available to draw over the source and ample room to exhaust hot air away from the source.
A second way to lower the temperature of a relatively hot component such as a light source is through the use of a heat sink. The heat sink increases the thermal mass and surface area of the component.
A purpose of the invention is to provide a system for more effectively cooling a light appliance within a substantially sealed environment.